Epidemiology and current situation of viral haemorrhagic disease of rabbits and the European brown hare syndrome in Italy

Abstract

Rabbit production is of considerable economic importance in Italy. In the last thirty years, meat production has risen and the number of intensive husbandry establishments has grown. The major region of production (about 60%) lies in the northern part of the country. In addition, approximately one million live animals and more than 14,000 tons of meat are imported yearly. More than 150,000 hares are also imported for restocking and hunting purposes. During the second half of the 1980s a "new" disease (X disease), characterised by haemorrhagic and degenerative lesions and high mortality, was observed on traditional farms in some regions. This form spread throughout the country between 1986 and 1988. In 1988, diagnostic research led to identification of a viral agent. Because of its morphology, the virus was at first considered a picornavirus. More recent research has included the virus in the Caliciviridae family. This agent reproduces the disease experimentally. Between 1988 and 1989, many intensive establishments in several regions were affected by the disease, known as viral haemorrhagic disease (VHD); the losses were always very high. In 1989, after mortality among free-living hares had been observed in the northern part of Italy for some years, the agent of the European brown hare syndrome (EBHS) was identified as being morphologically similar to the VHD virus. The antigenic relationship between VHD and EBHS and the possibility of cross-infection between rabbits and hares are currently being studied. Hygienic measures and vaccination are the most reliable methods of control. International cooperation has greatly helped in the study of the disease and in the adoption of control measures.